Method and Score Management Node for Supporting Service Evaluation Based on Correlated Service Events

1. A method for tracing at least one technical issue to support service evaluation of one or more services by obtaining a perception score P reflecting a user's experience of the one or more services delivered by means of a telecommunication network, the method performed by a score management node, the score management node comprising a processor and a memory containing instructions executable by the processor, the method comprising: receiving one or more network measurements related to a current service event of service delivery to the user within a predefined time length from at least one previous service event of service delivery to the user; determining a correlation level L reflecting the user's perception of the current service event as correlated with the at least one previous service event; determining, for the current service event, a quality score Q reflecting the user's perception of quality of service delivery and an associated significance S reflecting the user's perception of importance of service delivery, based on the one or more network measurements and the correlation level L; calculating the perception score P for the current service event as the quality score Q weighted by the associated significance S, wherein the perception score P is made available for the service evaluation, and wherein the score management node calculates a perception score P N for N network measurements as P N = ∑ n = 1 N ⁢ Q n ⁢ S n ∑ n = 1 N ⁢ S n , where Q n is a quality score for each network measurement n and S n is an associated significance for said network measurement n; and determining the at least one technical issue, based on the calculated perception score P, in the one or more network measurements associated with the current service event, wherein determining the at least one technical issue facilitates in improving the one or more services by one of eliminating and repairing the at least one technical issue for the one or more services.

2. The method according to claim 1 , wherein the score management node reduces the correlation level L over time by predefined steps at regular intervals after the current service event to reflect the user's fading memory of the current and previous service events together.

3. The method according to claim 1 , wherein the score management node increases the correlation level L each time a network measurement related to a new service event of service delivery to the user is received within the predefined time length from the at least one previous service event.

4. The method according to claim 1 , wherein the current and previous service events are of the same service type n, and wherein the score management node determines the correlation level L as a predefined correlation level L n of the service type n.

8. The method according to claim 1 , wherein M service events of service delivery to the user have occurred within the predefined time length, and wherein the score management node determines an overall correlation level for the M service events as an average of correlation levels L m,n of the current service event n and each previous service event m as L = ∑ m = 1 M ⁢ L m , n M .

9. The method according to claim 1 , wherein the score management node determines multiple pairs of the quality score Q and associated significance S based on network measurements related to multiple service events of service delivery to the user, and calculates the perception score P as an average of the quality scores Q weighted by their associated significances S.

10. The method according to claim 1 , wherein the one or more network measurements are related to at least one of: a time needed to download data, a time from a service request until delivery, a call drop rate, a data rate, or a data error rate.

11. The method according to claim 1 , wherein the score management node receives the one or more network measurements in a message according to a hyper-text transfer protocol (HTTP) or a file transfer protocol (FTP).

12. A score management node arranged to trace at least one technical issue for supporting service evaluation of one or more services by obtaining a perception score P reflecting a user's experience of the one or more services delivered by means of a telecommunication network, the score management node comprising a processor and a memory containing instructions executable by the processor, wherein the score management node is configured to: receive one or more network measurements related to a current service event of service delivery to the user within a predefined time length from at least one previous service event of service delivery to the user; determine a correlation level L reflecting the user's perception of the current service event as correlated with the at least one previous service event; determine, for the current service event, a quality score Q reflecting the user's perception of quality of service delivery and an associated significance S reflecting the user's perception of importance of service delivery, based on the one or more network measurements and the correlation level L; calculate the perception score P for the current service event as the quality score Q weighted by the associated significance S, wherein the perception score P is made available for the service evaluation, and wherein the score management node is configured to calculate a perception score P N for N network measurements as P N = ∑ n = 1 N ⁢ Q n ⁢ S n ∑ n = 1 N ⁢ S n , where Q n is a quality score for each network measurement n and S n is an associated significance for said network measurement n; and determine the at least one technical issue, based on the calculated perception score P, in the one or more network measurements associated with the current service event, wherein the determined at least one technical issue facilitates in improvement of the one or more services by one of eliminating and repairing the at least one technical issue for the one or more services.

13. The score management node according to claim 12 , wherein the score management node is configured to reduce the correlation level L over time by predefined steps at regular intervals after the current service event to reflect the user's fading memory of the current and previous service events together.

14. The score management node according to claim 12 , wherein the score management node is configured to increase the correlation level L each time a network measurement related to a new service event of service delivery to the user is received within the predefined time length from the at least one previous service event.

15. The score management node according to claim 12 , wherein the current and previous service events are of the same service type n, and the score management node is configured to determine the correlation level L as a predefined correlation level L n of the service type n.

19. The score management node according to claim 12 , wherein M service events of service delivery to the user have occurred within the predefined time length, and the score management node is configured to determine an overall correlation level for the M service events as an average of correlation levels L m,n of the current service event n and each previous service event m as L = ∑ m = 1 M ⁢ L m , n M .

20. The score management node according to claim 12 , wherein the score management node is configured to determine multiple pairs of the quality score Q and associated significance S based on network measurements related to multiple service events of service delivery to the user, and to calculate the perception score P as an average of the quality scores Q weighted by their associated significances S.

21. The score management node according to claim 12 , wherein the one or more network measurements are related to at least one of: a time needed to download data, a time from a service request until delivery, a call drop rate, a data rate, or a data error rate.

22. The score management node according to claim 12 , wherein the score management node is configured to receive the one or more network measurements in a message according to a hyper-text transfer protocol (HTTP) or a file transfer protocol (FTP).

23. A computer program storage product comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any one of claims 1 - 9 and 10 - 11 .